1. *Pediatrics and
2. §Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892;
3. ∥Animal Health Trust, Lanwades Park, Newmarket, Suffolk, United Kingdom
4. ¶Department of Comparative Medicine, Stanford University, CA 94305; and
5. †Surgery, and
6. ‡The Howard Hughes Medical Institute, The Johns Hopkins University School of Medicine, Baltimore, MD 21287;